Manufacture of organolead compounds



Petented Nov. 20, 1951 PATENT 1 OFFICE I I 575,323 J MA t'mKCijiiiftjE F ORGANOLEAD COMPOUNDS "iiimin Shapiro, Detroit, diiajzai fd. pe Witt, FEr HHaIE," Mic'hzg-assignoif's" t6 Ethyl ,Coi'poi'a tiony'New' York, 11., separation of neiawaie lire L'fiplieation December 9, 1950, r Seri'aINo. 2o0,-124 c a 3 Claims. (01. 26misfir The most importantofthe organolead comwhich forms asaitwi lith 1i m'etal'. Aiiion pounds is tetraethylleadwhich is made commerthose which 5511 be used iii my invention are the @5113? by reacting moneeodmm lead aney with ethyl, DIOIWL blifil and @HhYl ehlerise as Well ethyicmoriae in accordance with the-following e rrespon m'g bromides and amides, as

equation: as diethyls'uliat'e and triethylphosphat'e." I "hue tetraethyllead istheprmeipaieompeuna 4NaPb+4c2H5C1 (6 3: 1 m rs'eaesed herein means; of itsl'ar'gebfommereial f 11.e, ether aikyneaa eom' asunds; such a's tetrfqa Th Process has been e s ul bu has inethi ueaa, etrapr'o yuead, dimethyldiethyl? tarbais dvantaees among which are the ;i1ece mafia, ffnjethyltiie'thyllead, tetraphenyii-ead, fer Sit? of amine a sodiumead alloy and the ethyldiphenynead can be made by the preeess 6r t limitations myiei'q in ee three-fourths of my irrvemion. p the ieati is not utilized in the reaction. The temperature employed is pt critieamh'e unused lead must be reeev-er'ea and 're-a'i-leyed preferable range being between 50 and 1QO :(1.

with the sodium. pressure used is not emreei but should he A principal object of my invention is to proe1 1 eient at the emperature-mamas toihaifi 51 bifoess fr th'i'bii' avoiding the aikylatiug' agent in the ll'diiid 15ha'se1 the'ekbh's'iveallotihg eperati n;- no The time of reactio is between abputeojium eapeve-and 'othei'bbjeetsareabedfiiplished u't'e's and '5 hours. The ameufit of alkylatih eaeti'ng lead with alkylating "ag'nt iii th agent employed is not 'britifial air-excess iii/ell preseiiee of an additiii'n eompquna of a'n alkali the stoichiometric amoiifit'required in the abeye inetal and a pomycne aromatic lfijrdroaibbfi. general equation is preferred. Fer high'estiieldfi action can be generalized by renewing n; a slight stoichiometrie excess'of the alkali metal equatmn': I aromatic complex should be used although lesser H ambu'ii'cs'give prbpbr'ti'oriat'e fields and winresuit PPHRXHR Mm 7 T (ID increase ieia' used vehemently ""r'e R is an alkyl or arm raa-iea1-,'R'ssapes: aim the present process. e icar m'ati ia-l, M i a a i ta a our process can be used concurrently to line an inorganic aeid-r-adieal waichrerms a salt "p ye th' yield "of t present c mmercial prijeess it can be used independently in treatiiig tlie with the alkali metal;

- -It gimme be hated that the 'theoi'tlcal-"yildbi unrea'eted lead fro the present pro ss for ether the alkyllead compound based on the leal i rear forms of free lead. 'B'y coneu'irehtlyis *mean't times h of Present commerbial pre'eess. either adding the alkali metal complex albh'g 13150 the p y yei-ic arem'a'ti'e hy mca i5 'Withth'e other rea'eta fits tethe present preeess i idil? recovered can be reused in making oiffiist Conducting the rescuer; of the iares'lit the addition compound with the alkalimetal. preees and then adding the alkalimetal The meth d o making the eta p y- 'piex uch bveran reaction 'is expressedby eyclio' aromatic complex is Well-known and fully 40 'the'iolloivi'ng' musaative equation: lets isle v I w t t a Y 2R4Pb+8NaX-+ 6R' (HI) Such polycyclic aromatic complexes canbe first V v n I prepared and then used in my process, orthey Also in "place of sea-mm other metals, enerally can-be prepared in situ by addingrsodihm, a the alkali earth and alkali metals, well-known "p'olyeycl icaromatic and a 'solvehtflsuchasthose for thispurpose, an be alloyed i the l deseribed in the above menti'oned patents; or aiidusefd in' theab-bve reaction. Among such example, 1,2-dimethoxyethane, to the free-Llead metals are potassium an "calcium. V 7 and the alkylating agent. may of the.-alkali f'WhiIe catalysts are-net essentm to'biI'r Iii metals can be used; although sodium, potassium 'ventioi'i, certain amines, partiaumiy arom "c and lithium are preferred. Among. thepolyeyelic ai'n 'ehas' dix'nethi lahilin'e, ethylanili'ne, "raromatics which can be used in making the alkali p11 mine, 'phehylehedi'a inines and methyl metarearematic complexes are naphthalene, diethylaniline, improiie the yields obtained inbfijr phefiyl, 'phenanthrefie, and anthracene. process. I

Any of the alkylating agents heretofore used mention can -be best understood by or described in the priorarteanbe used, among referring to the following working examp es, yhioh arethe; a ky nd,'.aW:l-g, lides pr ferably wherein small quantities of themetal-polycydlie the iodides, bromides and chlorides, the dialkyl aromatic complexsare used-L If larger amounts sulfatesand the trialkyl phosphates. Ingeneral, are used even better yields are obtained although the "alkylatiifg and aiYIatiIFg agents are esters of :tlie resultsf's'howh hef'ih are 's'a'tisraetery fora inorganic acids having the proper alkyl or aryl Ebiitihzibtis ope'r-aitiibh."

xamp I L A chargeof 100 parts of NaPb alloy added to a reaction vessel, equipped with an agitator, a jacket for circulation of heating or cooling liquids, a reflux condenser, charg n and dis-- charging ports, liquid feed lines, and means for releasing the pressure. Liquid ethyl chloride in on the sodium charged.

the amount of 111 parts is added under pressure to the stirred solids in the vessel over a periodof one-half hour. By controlling the flow of liquid in the autoclave jacket and in the reflux con-1 denser the temperature of the reaction mass is permitted to rise from an initial temperature of 50 C. to a temperature of 70 C. during this feed period. The pressure in the autoclave during this feed rises to75 poundsper square inch gauge, where it is maintained. The temperature of the stirred reaction mixture is maintained at 70 C. for an additional minutes maintaining the 75- pound pressure. At the end of this period an additional 53 parts of ethyl chloridewas charged to the reaction vessel along with a solution comprising 35.9 parts of sodium-naphthalene complex, 83 parts or 1,2 -,dimethoxyethane' and 38 parts of dimethylaniline. TThe resulting mixture was heated for an additional period of 180 minutes at'a temperature of 70 C., whereupon the temperature wa'sreduced to C. and the contents of the reaction vessel were discharged to a steam still. Upon recovery by steam-distillation of the tetraethyllead produced, the yield of tetraethyllead was determined to be 34.2 parts, corresponding to a yield of 63.5 per cent based upon the amount of sodium charged during the reaction as both sodium-lead alloy and sodium naphthalene complex as determined according to Equation III, or 24.4 per cent based on the amount of lead originally charged to the reaction.

Example II heated to a temperature of 70 C. with agitation for a period of 180 minutes. At the end of this time the contents of the reaction vessel were cooled to 25 C. and'discharged to asteam still and the product tetraethyllead was recovered as in the foregoing example. The yield of product from this operation was 6.6 parts, or 22.4 per cent based upon the sodium charged as sodium naphthalene complex in accordance with Equation II.

Example III To 100 parts of free lead obtained iii-accordance with the procedure, of Example II, in a similar reaction vessel, was added 550 parts of ethyl iodide, 221 parts of a solution of 67 parts of sodium-naphthalene complex in 154 parts of 1,2-

dimethoxyethane. By'a series of operations similar to the above example, 24 parts of tetraethyllead was produced corresponding to a yield of 61 per cent, based upon the sodium charged in accordance with Equation II, or 15.4 per cent based on the lead charged.

. Example IV In an operation similar to Example III but wherein 107 parts of dimethylaniline was added Example V wfIn.an ioperationlsimilar to that described in ,ExamplelII above; with the exception that the 1,2-dimethqxyethane solution of sodium-naphthalene complex was replaced by a solution of 84.8 parts of lithium-naphthalene complex, in

'- 189 parts of 1,2-dimethoxyethane, a yield of tetraethyllead corresponding to 24.6 per cent was obtained, based on the lithium charged in accordance with EquationII.

Example VI y In the reaction vessel of Example I 'wa scharged parts of lead resulting from the alkylationo'f sodium-lead alloy'wi'th ethyl chloride, 550 parts of ethyl iodide, parts of 1,2-dimethoxyethane, 16 parts of dimethylaniline, and parts ofa dispersion previously prepared by vigorously agi tating a mixture of 23 parts of molten sodium in 127 parts'of naphthalene at atemperatureoi 105 C. This charge was heated to a temperature of 80 C. for a period of 3 hours, whereupon it was discharged to a steam still and the tetraethyllead recovered by steam distillation. The yield of tetraethyllead in this operation was 19.? per cent based upon the sodium dispersion charged to the reaction vessel in accordance with Equation II. I

We claim: I

l, A process for making tetra-substituted organolead compounds comprising reacting lead with an agent selected from the class consisting I-IYMIN VSI-IAPIRO. EARL G. DE WITT;

REFERENCES CITED The following references are ofrecord in the file of this patent:

Chemical Abstracts, vol. 36, 1595 19-4,2) 

1. A PROCESS FOR MAKING TETRA-SUBSTITUTED ORGANOLEAD COMPOUNDS COMPRISING REACTING LEAD WITH AN AGENT SELECTED FROM THE CLASS CONSISTING OF ALKYLATING AND ARYLATING AGENTS IN THE PRESENCE OF AN ALKALI METAL-POLYCYLIC AROMATIC HYDROCARBON COMPLEX, SAID AGENT HAVING THE HYDROCARBON RADICALS IN QUESTION AND HAVING A NEGATIVE RADICAL WHICH REACTS WITH THE ALKALI METAL IN SAID ALKALI METAL COMPLEX. 